In a radio communication system, a radio terminal performs handover to switch its connection destination to a radio base station having better conditions. To enable execution of handover, the radio base station notifies the radio terminal connected to the radio base station itself of handover candidate information including base station identification information for identifying radio base stations in a neighborhood of the radio base station itself (referred to below as “neighboring radio base station”) (see Patent Document 1). Such handover candidate information is also referred to as a neighbor list.
The radio terminal performs a search (so-called cell search) on the neighboring radio base stations which are handover candidates, according to the handover candidate information notified by the radio base station. For example, the radio terminal captures, according to the handover candidate information, a radio signal (such as a pilot signal) transmitted by a neighboring radio base station to thereby detect the neighboring radio base station, and performs handover to the neighboring radio base station if the signal quality of the radio signal is at a certain level or higher.
Recently, a radio relay station for relaying data transmitted and received by a radio base station and a radio terminal has been widely used. The radio terminal is capable of performing not only handover between radio base stations but also handover from a radio base station to a radio relay station. Accordingly, the radio base station is required to notify the radio terminal of handover candidate information including not only the base station identification information but also relay station identification information for identifying radio relay stations which are handover candidates (specifically, radio relay stations connected to the radio base station).